Core/Creatures: Don't require creature.modelid to be one of linked creature_template models

Port From (https://github.com/TrinityCore/TrinityCore/commit/7cafeb46b3b1f3eea3c966c20f9ef1efe68dfbdc)

Source/Game/Entities/Creature/Creature.cs

@@ -1355,7 +1355,10 @@ namespace Game.Entities
             Cypher.Assert(data.SpawnId == m_spawnId);
 
             data.Id = GetEntry();
-            data.displayid = displayId;
+            if (displayId != 0)
+                data.display = new(displayId, SharedConst.DefaultPlayerDisplayScale, 1.0f);
+            else
+                data.display = null;
             data.equipmentId = (sbyte)GetCurrentEquipmentId();
 
             if (GetTransport() == null)

Source/Game/Entities/Creature/CreatureData.cs

@@ -259,7 +259,7 @@ namespace Game.Entities
 
     public class CreatureData : SpawnData
     {
-        public uint displayid;
+        public CreatureModel display;
         public sbyte equipmentId;
         public float WanderDistance;
         public uint currentwaypoint;